High capacity linear valve cage

Abstract

A cage for a control valve has a circumferential wall having inner and outer surfaces, a plurality of first passages formed through the wall, and a plurality of second passages formed through the wall. The plurality of first passages each include an upper portion and a lower portion that is tapered in a direction away from the upper portion. The plurality of second passages are positioned between adjacent lower portions of first passages.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Patent Application No. 62 / 240,089, entitled “High Capacity Linear Valve Cage” and filed Oct. 12, 2015, the entire disclosure of which is hereby incorporated by reference herein.FIELD OF THE DISCLOSURE[0002]This disclosure relates generally to fluid regulators / control valves and, more particularly, linear valve cages for fluid regulators / control valves.BACKGROUND[0003]In typical fluid regulators / control valves, a valve cage may provide guidance for a valve plug as the valve plug moves from a closed position in which the valve plug sealingly engages a valve seat to an open position in which the valve plug is disposed away from the valve seat. When the valve is in the open position, fluid flows from a valve inlet, passes through a passage between the valve seat and the valve plug, passes through the valve cage, and exits through a valve outlet. In addition to guiding the valve plug, a valv...

AI Technical Summary

Benefits of technology

The present invention relates to a control valve and a fluid regulator comprising the control valve. The control valve includes a valve body with an inlet and an outlet, a valve plug, and a valve cage. The valve plug is movable between a closed position and an open position. The valve cage includes a circumferential wall with a plurality of first passages and a plurality of second passages. The first passages extend between the inner surface and the outer surface of the circumferential wall and each include an upper portion and a lower portion, wherein the lower portion is tapered in a direction away from the upper portion. The second passages extend between the inner surface and the outer surface of the circumferential wall and are positioned between adjacent lower portions of the first passages. The technical effects of the invention include improved control of the valve plug and increased fluid flow through the control valve.

Problems solved by technology

Unfortunately, one drawback of high flow valve cage 300 is that the high initial fluid flow makes high flow valve cage 300 unstable since there is a large initial flow of fluid that surges through valve cage 300.

This can cause cavitation and other undesirable fluid flow issues.

However, one drawback of linear valve cage 400 is that in certain systems, the initial fluid flow through passages 410, which provides the stable fluid flow, is too small and allows pressure to build up within control valve 100.

This pressure build up can have undesirable affects, such as setting off safety pressure relief valves in the system due to the increased pressure, before valve plug 135 has moved far enough to allow a greater fluid flow through passages 410.

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